# Pounds per square inch

(Redirected from Psi)

Pounds per square inch or PSI is an imperial unit of pressure. Using the imperial units of pounds and square inches, it is a measure of force per unit area. Since it is acting on a much smaller area than the pascal, 1 PSI is much more pressure than the metric unit.

PSI are often used for tire pressure and other situations where gauge pressure is being measured instead of absolute pressure.